The present invention relates to the cycling and treatment of rinse water in photographic processes and more particularly to a compact and simplified system for handling and treatment of rinse water utilized in installations which develop photographic film and produce prints.
Recent years have witnessed the proliferation of establishments which process film of customers and have them ready for pick up in a very short period of time such as in an hour. Under this marketing scheme it is not possible or practical to send the undeveloped film to a control plant for processing where the handling and treatment of waste rinse water can more readily be controlled and the advantages of scale can be brought to bear on the problem of eliminating waste products in the rinse water which cannot be disposed of locally.
Current regulations of local, state and federal government agencies severely restrict, regulate, or disallow the discharge of any kind of waste materials, such as photographic chemical rinse water, into municipal sewage systems or into the ground by way of cesspools and sanitary landfills.
Thus the local establishment which does its own photographic processing is faced with the conflicting requirements of not being able to dispose locally through its own sanitary system the rinse water used in the processing of its photographic products and the need either to install at great cost the proper waste treatment equipment for use with its locally generated rinse water or to ship at great expense (sometimes illegally) the waste rinse water for reprocessing at a central plant.
Existing waste disposal systems are generally designed for large scale operations and presume the availability of highly skilled personnel for their operation and maintenance. Such systems are shown in a variety of U.S. patents.
U.S. Pat. Nos. 2,997,438 shows apparatus for the removal of silver from photographic hypo baths. In modern photographic processes, silver is not the only material of interest for recovery, and there are other contaminants present which prevent the disposal of the liquid.
U.S. Pat. No. 4,054,503 discloses portable apparatus for recovering metal from metal bearing solutions. This device also is primarily concerned with the recovery of silver.
U.S. Pat. Nos. 4,069,127, 4,149,954, and 4,319,971 teach the use of electrolytic methods and apparatus for removing certain metals from solution. Electrolytic systems are complex and not suitable for use where there is very little in the way of technical support available. In addition, discharge into the sanitary system is still required.
U.S. Pat. No. 4,437,968 discloses waste water purification and recycling apparatus in which waste water is boiled to produce steam leaving the waste products in concentrated form for removal. This system can only be employed in a large scale facility and is not available where relatively small amounts of liquid wastes are to be decontaminated.